• CN：11-2187/TH
• ISSN：0577-6686

›› 2012, Vol. 48 ›› Issue (14): 32-37.

• 论文 •

### 纯铜微镦粗过程尺寸效应的试验研究

1. 山东大学液固结构演变与加工教育部重点实验室;伍伦贡大学机械、材料和机电一体化学院
• 发布日期:2012-07-20

### Experimental Research on Size Effect of Micro Upsetting of Pure Copper

WANG Guangchun;ZHENG Wei;JIANG Hua;JIANG Zhengyi

1. Key Laboratory for Liquid-solid Structural Evolution and Processing of Materials of Ministry of Education, Shandong University School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong
• Published:2012-07-20

Abstract: The process of pure copper micro-cylinder upsetting is performed by a micro universal testing machine. Through the heat treatment and precision wire cutting technology, the specimens are designed with different dimensions and grain sizes. The effects of grain size and specimen size on the flow stress are investigated, respectively. It is found that the flow stress decreases with the miniaturization of the specimen size and the relationship between flow stress and volume fraction of surface grain is linear. The effect of grain size on the flow stress is indistinct as the specimen is larger, but the flow stress of the specimen with larger grain size is obviously lower than that with small size. The surface of the micro-forged specimens show significant inhomogeneous deformation as the specimen size is smaller. The size effects due to the changing of specimen size and grain size can be explained by surface model and fine grain strengthening theories. Meanwhile, the scale parameter is introduced to quantify the size effect and thus the linearly changing of follow stress with the volume fraction φ can be explained.